This proposal outlines a five year plan aimed at providing the scientific background and tools necessary for an active investigative career. Phase I focuses heavily on a didactic component of coursework at Harvard University, attendance at seminars at Harvard/MIT/MGH and the acquisition of basic skills in Dr. Henry Kronenberg's laboratory. The laboratory work will involve initially the cloning and sequencing of the gene for the vitamin D receptor, leading subsequently to studies aimed at defining the functional domains, targets of action, and overall mechanisms of action of this steroid receptor. The theoretic framework and techniques learned in phase I will then be applied to a phase II project. Several possibilities for this are outlined, all involving the application of the tools of molecular biology to a problem of interest in endocrinology.